Heavy industries such as steel making, coal gasification, metal refineries, power plants and cement making units emit a significant amount of carbon dioxide (CO2). Taking Singapore, for example, it was estimated that amount of carbon dioxide from power plants will exceed 20 million tonnes per year for the next decade (see TABLE 1).
TABLE 1Carbon dioxide (CO2) emissions from power plants in Singapore (2007-2017)2007 Energy and CO2 Emission2017 Energy and CO2 EmissionCO2EmissionCO2EmissionEnergyEmissionrateEnergyEmissionratePower PlantMWh/aMt CO2/at CO2/hrMWh/aMt CO2/at CO2/hrTUAS8,867,2754.0045717,100,00013.201507PULAU SERAYA8,297,8683.9344813,000,0006.00685SENOKO11,200,0004.4550811,500,0004.56520PULAU MERLIMAU02,931,1241.29147ISLAND POWER02,537,8751.27145PULAU SAKRA2,090,1030.871002,177,4970.91104SINGAPORE CHEMICAL684,5770.38431,610,5930.8395JURONG325,7140.1518363,8600.1719SINGAPORE OLEFINS318,4060.1517332,2270.1618CHANGI WWTP257,3030.1214276,9990.1315SMPO COGEN173,3210.1112182,3920.1113PASIR PANJANG185,0810.0910200,6640.1011Total32,399,64814.352,213,23028.7Source: http://carma.org/region/detail/169
Carbon dioxide capture and storage by mineralization has been proposed as a possible technology to reduce global carbon dioxide levels. The technology may include extracting cations from feed material such as rocks, and combining the cations with carbon dioxide to form a stable carbonate material. Due to the large quantities (gigatonnes) of material involved, ability to extract metal from the feed material at high efficiencies is important. Limitations to existing processes include low metal extraction yields and high energy consumption, due to removal of water which has high latent and sensible heat.
In view of the above, there exists a need for improved methods of producing metal carbonate from an ultramafic rock material, thereby capturing carbon dioxide from the atmosphere or environment, which overcome or at least alleviate one or more of the above-mentioned problems.